Cooking range burner head assembly

ABSTRACT

A burner assembly includes a substantially annular two-piece burner head having a base and a top. A plate is located in a central opening of the burner head and includes a slot for holding a pilot burner. Burner head annular channels incorporate one or more air dams to provide a backpressure feature within the burner head for more even flame height and stability.

CROSS-REFERENCES

This application is a continuation-in-part of U.S. Ser. No. 11/030,652, filed Jan. 5, 2005, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to gas fired cooking ranges and, more particularly, to burner head assemblies used in such ranges.

BACKGROUND

Gas fired cooking ranges have achieved wide acceptance in both residential and commercial kitchens. A known design for gas fired cook tops in ranges includes separate burner assemblies for each cooking location, with each burner assembly including a venturi and a burner head having gas-emitting orifices. It is known to arrange the orifices so that the flames are spread widely, and are directed across the bottom surface of a vessel placed on a grate above the burner. These burners have included orifices in outwardly facing surfaces of the burner head, so that flames are directed outwardly from the burner head. A disadvantage of this design is that the outermost orifices are exposed to fouling from boil-overs and spills in which food can flow along outer surfaces of a cooking vessel above the burner and drip from the vessel onto the burner head.

Factors such as flame intensity and efficiency, burner assembly cleanability and fuel consumption efficiency are important to both residential and commercial installations. However, these factors may be of greater importance for commercial kitchens where a great number of meals may be prepared on each cook top in a relatively short period of time. The time required for completing a food course, including initial preparation time for heating and actual cooking time, can be reduced by efficient burner performance. If the flame from a burner spreads outwardly beyond the vessel being heated, or wicks up the side of the vessel, heat transfer efficiency decreases. Since commercial kitchens can be hectic environments, boil-overs and spills are common. Therefore, cleanability is important, and it is advantageous to reduce the time required for disassembling

and reassembling the cook top for thorough cleaning. Maintaining burner performance in spite of spills and boil-overs during food preparation is also important.

What is needed in the art are burner assemblies that are reliable, use fuel efficiently, heat vessels quickly and can be disassembled and reassembled efficiently for thorough cleaning of the cook top.

SUMMARY

In one aspect, a two-piece burner assembly includes an annular base and cover. Gas-emitting orifices are provided in the cover only in upwardly and/or inwardly facing surfaces. A restrictor plate positioned within the annular burner controls the flow of secondary air for efficient burner performance.

In another aspect, a gaseous fuel burner assembly includes a venturi and an annular burner head associated with the venturi for the combustion of gaseous fuel from the venturi. The burner head has outwardly facing, upwardly facing and inwardly facing surfaces. The burner head defines gas-emitting orifices only through the upwardly and/or inwardly facing surfaces of the burner head.

In another aspect, a gas fuel burner head includes a substantially annular base and a substantially annular cover having gas-emitting orifices on only upwardly and/or inwardly facing surfaces of the cover. A restrictor plate limits the flow of air through the center of the substantially annular base and top.

In a further aspect, a gaseous fuel burner assembly includes a venturi, an annular burner head associated with the venturi for the combustion of gaseous fuel received in the burner head from said venturi. The annular burner head has a center opening therethrough for flow of ambient secondary combustion air. The burner head includes a base defining a substantially annular channel between an inner wall and an outer wall, the annular channel having an open top, the burner head including a removable cover on the annular channel, the cover having outwardly facing, upwardly facing and inwardly facing surfaces. The burner head defines gas-emitting orifices. A plate is disposed in said center opening and including a slot for holding a pilot light burner head.

In yet another aspect, a gaseous fuel burner assembly includes a venturi, an annular burner head associated with the venturi for the combustion of gaseous fuel received in the burner head from the venturi. The annular burner head has a center opening therethrough for flow of ambient secondary combustion air. The burner head includes a base defining a substantially annular channel between an inner wall and an outer wall, the annular channel having an open top. The burner head includes a removable cover on the annular channel, the cover having gas emitting orifices therein. The annular channel includes an air dam extending between inner and outer walls that form the annular channel.

Other features and advantages of the invention will become apparent to those skilled in the art upon review of the following detailed description, claims and drawings in which like numerals are used to designate like features.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a cooking range having burner head assemblies in accordance with the present invention;

FIG. 2 is a perspective view of a partly disassembled burner head assembly in accordance with the present invention;

FIG. 3 is a perspective view of a burner head cover of the burner head assembly shown in FIG. 2;

FIG. 4 is a cross-sectional view of a burner head in accordance with the present invention;

FIG. 5 is a top view of a restrictor plate in accordance with the present invention;

FIG. 6 is cross-sectional view of a burner head in use;

FIG. 7 is a perspective partial view of an alternative embodiment of a burner head assembly;

FIG. 8 is a perspective of a pilot holding plate;

FIG. 9 is a cross-section of a burner head cover; and

FIG. 10 is an enlarged partial cross-section of the burner head cover of FIG. 9.

Before the embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein are for the purpose of description and should not be regarded as limiting. The use herein of “including”, “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof, as well as additional items and equivalents thereof.

DETAILED DESCRIPTION

Referring now more specifically to the drawings and to FIG. 1 in particular, numeral 10 designates a cooking range having a burner head assembly 12 (FIG. 2) in accordance with the present invention provided as part of a cook top 14. Range 10 further includes an oven 16. The present invention is useful for commercial ranges and residential ranges, and the particular outward configuration of range 10 shown in FIG. 1 is merely exemplary.

Range 10 is a gas fired range, having a gas circuit (not shown) for supplying combustible gas to each burner assembly 12 provided at several cooking locations on cook top 14, and to an oven burner assembly, not shown, for heating the interior of oven 16. As those skilled in the art will understand readily, range 10 has a plurality of flow control valves 18 for initiating, terminating and controlling the rate of gas flow to cooking locations on cook top 14. Range 10 is supported on casters 20, by which range 10 can be moved a short distance to clean the area around the range.

Burner head assembly 12 includes a first burner head 22 and a second burner head 24 at which combustion of gaseous fuel occurs. A single piece, monolithic casting 30 forms a first venturi 32 associated with a first burner head base 34 and a second venturi 36 associated with a second burner head base 38.

First venturi 32 and second venturi 36 provide a flow of gas and primary combustion air for combustion at first and second burner heads 22, 24, respectively, in front and back locations, respectively, on cook top 14. First and second gas receivers 40, 42 are provided on first venturi 32 and second venturi 36, respectively. As known to those skilled in the art, each receiver 40, 42 is aligned with a different control valve 18 to receive gas therefrom when the control valve 18 is opened to allow gas to flow therethrough. Receivers 40, 42 also admit a flow of ambient air to mix with the combustible gas in first venturi 32 and second venturi 36 to provide a combustible mixture to burner heads 22, 24.

FIG. 2 illustrates burner head assembly 12 in a partial state of disassembly, to better illustrate features of the present invention. Each burner head base 34, 38 is a substantially annular body defining an open top annular channel 44 between an inner wall 46 and an outer wall 48. Annular channel 44 of burner head base 34 is visible in FIG. 2. A burner head cover 50 is provided on each burner head base 34, 38, with cover 50 on burner head base 38 being shown in FIG. 2. Each cover 50 has a plurality of gas-emitting orifices 52 therein through which a mixture of combustible gas and primary combustion air is emitted. For clarity, only some orifices 52 and not all orifices 52 are identified with a reference numeral in the drawings.

In the embodiment illustrated, first venturi 32 and second venturi 36 are configured with first burner head base 34 and second burner head base 38, respectively, to swirl the combustion mixture in opposite directions. In the embodiment shown in FIG. 2, first venturi 32 is configured with first burner head base 34 to swirl the combustion gas in a clockwise direction, and second venturi 36 is configured with second burner head base 38 to swirl the combustion gas in a counter-clockwise direction. It should be understood that the rotational directions within first and second burner head bases 34, 38 can be reversed or can be both in the same direction, either clockwise or counter-clockwise. Alterations in the orientations and angular relationships between first venturi 32 and first burner head base 34 and between second venturi 36 and second burner head base 38 can be used to make such changes in direction.

Burner head 24 and the components thereof can be seen more clearly in FIGS. 3 and 4. Burner head 50 fits on burner head base 38 and is a multi-surfaced, generally annular structure. Burner head 50 includes a primarily upwardly facing surface 54, which is a top surface of cover 50. Surfaces radially outward of upwardly facing surface 54 are generally outwardly facing, and include an upwardly and outwardly facing surface 56 adjacent upwardly facing surface 54 and a mostly outwardly facing surface 58, which is the outermost surface of cover 50.

Radially inwardly from top surface 54 in cover 50 are multiple surfaces that are generally inwardly facing. An innermost, mostly inwardly facing surface 60 is provided adjacent an inward edge 62 of cover 50. An intermediate surface 64 adjoins innermost surface 60 with top surface 54. Intermediate surface 64 is inwardly and upwardly facing.

Orifices 52 are provided only in the upwardly facing top surface 54 and generally inwardly facing surfaces 60 and 64. Orifices 52 are not provided in generally outwardly facing surfaces 56 and 58. Thus, flames 66 (FIG. 6) arising from combustion of fuel at burner head 24 are directed upwardly and inwardly and are concentrated against the center area of a bottom surface of a vessel 68 supported on a grate 70 above burner head 24. This is in contrast to known burner designs in which flames are directed outwardly to spread across the surface of a vessel supported above the burner, in which the flames may spread beyond, or wick up the side of the vessel. Concentrating the flames toward the center of the vessel improves heat transfer performance, shortening time required to achieve boiling of liquids in the vessel, and otherwise reducing the time required for heat-up of the vessel. Upwardly and inwardly facing surfaces 54, 60 and 64 are shielded from drips along outer surfaces of vessels above the burner, and therefore are less prone to fouling from boil-overs and spills.

As seen most clearly in the cross-sectional view of FIG. 4, cover 50 is removably engaged on burner head base 38. Inner edge 62 defines an inner lip 72 removably seated on inner wall 46 of burner head base 38, and an angular surface 74 is directed laterally and upwardly from inner edge 62 to inner lip 72. Angular surface 74 engages inner wall 46 and slides therealong as cover 50 is placed on burner head base 34 or 38, and directs and centers burner head cover 50 for proper positioning and seating on burner head base 34, 38. Cover 50, therefore, is self-centering. Cover 50 further includes an outer edge 80 defining an outer lip 82 that engages outer wall 48 of burner head base 34, 38. Cover 50 is thus sealed on inner wall 46 and outer wall 48 so that gas flow through channel 44 is emitted only through orifices 50.

As shown most clearly in FIG. 4, inner edge 62 is disposed lower than outer edge 80, and a zone of orifices 52 through inner most surface 60 are lower than outer edge 80. Orifices 52 through innermost surface 60 provide multiple low, centrally originating flames even on large burners.

For efficient combustion, the present invention provides control of secondary airflow in both volume and direction. The flow of air through the center opening of annular burner heads 22 and 24 is controlled by a restrictor plate 90 disposed within the center opening. Restrictor plates 90 have lateral tabs 92 secured to feet 94 of bases 34 and 38, to provide a substantially annular gap 96 between restrictor plate 90 and burner head base 38 and/or cover 50. Three tabs 92 are shown in the drawings, but fewer or more can be used. Attachment can be by screw, bolts or other suitable means. Further control of secondary airflow is provided through a central aperture 98 in restrictor plate 90. A slot 100 is provided in restrictor plate 90, to hold a pilot burner (not shown) of a pilot light system for igniting fuel at burner heads 22, 24.

Through selection of the size and shape of annular gap 96 and central aperture 98 for the size and performance of the burner, the proper amount of secondary air is allowed to enter and is properly directed for more efficient burner performance. Secondary combustion air flowing through annular gap 96 rises through burner head 22 or 24, near to and first encountering the lower originating flames from orifices 52 in innermost surface 60. The secondary combustion air provides complete, efficient combustion of gas emitted from orifices 52 in innermost surface 60. Remaining air from annular gap 96, and air rising through central aperture 98 disperses outwardly, providing secondary air for complete, efficient combustion of gas emitted from orifices 52 in intermediate surface 64 and in top surface 54. With flames directed upwardly and inwardly, air for secondary combustion is limited primarily to the air that flows upwardly through annular burner heads 22 and 24, and can be controlled by restrictor plate 90. This is in contrast to known burner designs with flames originating from orifices in outwardly facing surfaces that are exposed to virtually limitless and uncontrollable flow of ambient air.

It should be understood that the detailed structures described above for burner head 24, including a cover 50 and a restrictor plate 90, are provided in similar manner and construction for burner head 22.

The single casting 30 for both burner head 22 and burner head 24 having facilitates efficient disassembly and re-assembly for cleaning. Casting 30 can be removed with restrictor plates 90 fastened thereto, and with covers 50 remaining in place on burner head bases 34 and 38. Alternatively, covers 50 can be removed from burner head bases 34 and 38 before casting 30 is removed from cook top 14. Since covers 50 are self-centering and self-positioning on bases 34 and 38, removal and re-installation for cleaning are quick and easy.

Referring now to FIGS. 7-10, an alternative embodiment of a burner head assembly is shown. Burner head assembly 100 includes a first burner head 102 and a second burner head 104 at which combustion of gaseous fuel occurs. A single piece, monolithic casting forms a first venturi 106 associated with a first burner head base 108 and a second venturi 110 associated with a second burner head base 112. Gas receivers 114, 116 are provided on the respective venturis. Each burner head base 102, 104 is a substantially annular body defining an open top annular channel 118, 120 between an inner wall 122, 124 and an outer wall 126, 128. In the embodiment illustrated, venturi 106 and venturi 108 are configured with the respective burner head bases 102 and 104 to swirl the combustion mixture in opposite directions along the respective channels 118 and 120, but variations are possible.

A burner head cover 130 (FIG. 9) is provided on each burner head base and includes a plurality of gas-emitting orifices 132 therein through which a mixture of combustible gas and primary combustion air is emitted. The burner head cover 130 fits on the burner head bases and is a multi-surfaced, generally annular structure. Burner head 130 includes a primarily upwardly facing top surface 134. Surfaces radially outward of upwardly facing surface 134 are generally outwardly facing, and include an upwardly and outwardly facing surface 136 that angles downwardly and outwardly from surface 134 to a further downwardly angled surface 138 that extends downwardly and outwardly to an outermost surface 140 that is substantially vertical. By way of example, the downward angles θ₁ and θ₂ relative to the top surface 134 may be between ten and twenty degrees (e.g., about 15 degrees) for θ₁ and between forty and fifty degrees (e.g., about 45 degrees) for θ₂. Radially inwardly from top surface 134 is inwardly and downwardly angled surface 142 which extends inward to a inwardly and further downwardly angled innermost surface 144. Notably, in this embodiment gas orifices 132 are located on each of the surfaces 144, 142, 134 and 136, but surfaces 138 and 140 lack any gas emission orifices. Thus, this alternative embodiment includes gas orifices on the outwardly facing surface 136 that is closest to the top surface 134, but not on any other outwardly facing surfaces.

Cover 134 is configured to be removably engaged on burner head base. Inner edge 146 defines an inner lip 148 that, in assembled from, is removably seated on inner wall 122 or 124 of the burner head base, and an angular surface 150 extends radially inwardly and downwardly from the lip 148. Angular surface 150 engages the inner wall 122 or 1124 and slides therealong as cover 134 is placed on burner head base, and directs and centers burner head cover for proper positioning and seating on burner head base. Cover 134, therefore, is self-centering. Cover 134 further includes an outer edge 160 defining an outer lip 162 that engages the outer wall 126 or 128 of the burner head base. Notably, lip 148 and lip 162 lie in the same plane. In this regard, and referring again to FIG. 7, it can be seen that the top surfaces of the inner wall 122, 124 and outer wall 126, 128 of each burner head also lie in the same plane. This configuration simplifies machining operations for both the burner heads and the cover.

As shown in FIGS. 7 and 8, a plate structure 164, 166 is mounted in the center opening of each burner head and the plate structure 164, 166 includes side mount flanges 168 and 170 with openings that align with openings in mounting tabs that extend radially inward from the inner wall 122, 124, and a raised central flat 172 that includes a slot 174 for receiving and holding a pilot burner head in a manner similar to the slot 100 in the embodiment of FIG. 2. The slot 174 is generally elongated and includes a slight inward pinch or narrowing 176 near the closed end of the slot that aids in holding a pilot burner head in desired position at the closed end of the slot.

The annular channels 118 and 120 of the embodiment of FIG. 7 also include one or more air dam features to help stabilize flow from the gas orifices in the head cover 134. Specifically, each channel includes a respective air dam 180, 182 that is located proximate a gaseous fuel inlet 184, 186 to the annular channel such that gaseous fuel entering the annular channel travels around the annular channel toward the air dam at a downstream location to flow, which flow direction is indicated by arrows 188, 190. The air dams take the form of walls extending between the inner and outer walls of the channels. Air dams 180 and 182 are full channel height, rising from the flow of the channel up to the top edges of the inner and outer walls. Upstream of the air dams 180 and 182 are additional air dams 192 and 194, which extend upward from the channel floors only partially, thus having heights that are less than the channel height, with respective top surfaces of the air dams 192 and 194 being lower than the top edges of the inner and outer walls that define the channels. As the air fuel mixture enters the annular channel it circles around and is emitted through the burner head ports or orifices in the cover 134. Without the air dams, some of the air fuel mixture will go all the way around the channel until it meets up with a fresh mixture at the opening into the space, creating a slightly higher pressure at that location resulting in a slight unevenness in emitted flame height. The air dams create a slight back pressure to even out the flame height. The air dams also slow down the mixture allowing the flame to be more stable at the ports. The air dams 192, 194 may typically be offset circumferentially upstream from the air dams 180, 182 by between about thirty and ninety degrees (e.g., about 60 degrees), but variations are possible.

Variations and modifications of the foregoing are within the scope of the present invention. It is understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present invention. The embodiments described herein explain the best modes known for practicing the invention and will enable others skilled in the art to utilize the invention. The claims are to be construed to include alternative embodiments to the extent permitted by the prior art. 

1. A gaseous fuel burner assembly comprising: a venturi; an annular burner head associated with said venture for the combustion of gaseous fuel received in said burner head from said venturi, said annular burner head having a center opening therethrough for flow of ambient secondary combustion air; said burner head including a base defining a substantially annular channel between an inner wall and an outer wall, said annular channel having an open top, said burner head including a removable cover on said annular channel, said cover having outwardly facing, upwardly facing and inwardly facing surfaces; said burner head defining gas-emitting orifices; a plate disposed in said center opening and including a slot for holding a pilot light burner head.
 2. The burner assembly of claim 1, said upwardly facing surfaces including a top surface, said inwardly facing surfaces including a first inner angled surface extending downwardly and inwardly from the top surface to a second inwardly angled surface that extends downwardly and inwardly from the first inner angled surface.
 3. The burner assembly of claim 2, said orifices defined in at least each of said top surface, said first inner angled surface and said second inner angled surface.
 4. The burner assembly of claim 3, said outwardly facing surfaces including a first outer angled surface extending downward and outward from the top surface to a second outer angled surface that extends downward and outward to a substantially vertical outermost surface, said orifices are located only in each of said top surface, said first inner angled surface, said second inner angled surface and said first outer angled surface, such that said second outer angled surface and said outermost surface lack any orifices.
 5. The burner assembly of claim 1, said cover having an outer edge defining an outer lip engaging said base and an inner edge defining an inner lip engaging said base.
 6. The burner assembly of claim 5, said inner lip and said outer lip lying in a common plane.
 7. The burner assembly of claim 1, including a monolithic body forming first and second gas receivers, first and second venturis and first and second burner head bases; and said burner assembly having first and second burner head covers removably engaged on said first and second burner head bases.
 8. The burner assembly of claim 9, said first burner head base and said second burner head base configured with said first and second venturis, respectively, for developing gas flows through said first and second burner head bases directed oppositely with respect to each other.
 9. The burner assembly of claim 1 wherein said annular channel of said base is defined by inner and outer walls, and an air dam extends across the annular channel between the inner wall and the outer wall.
 10. The burner assembly of claim 9 wherein the air dam is located proximate a gaseous fuel inlet to the annular channel such that gaseous fuel entering the annular channel travels around the annular channel toward the air dam.
 11. The burner assembly of claim 10 wherein the air dam is a first air dam having a full channel height, the assembly further includes a second air dam extending between the inner wall and the outer wall.
 12. The burner assembly of claim 11 wherein the second air dam is located upstream of the first air dam by between forty and sixty degrees, the second air dam having a partial channel height.
 13. A gaseous fuel burner assembly comprising: a venturi; an annular burner head associated with said venture for the combustion of gaseous fuel received in said burner head from said venturi, said annular burner head having a center opening therethrough for flow of ambient secondary combustion air; said burner head including a base defining a substantially annular channel between an inner wall and an outer wall, said annular channel having an open top, said burner head including a removable cover on said annular channel, said cover having gas emitting orifices therein, said annular channel including an air dam extending between inner and outer walls that form the annular channel.
 14. The burner assembly of claim 13 wherein the air dam is located proximate a gaseous fuel inlet to the annular channel and downstream of a flow direction of gaseous fuel into the annular channel.
 15. The burner assembly of claim 14 wherein the air dam is a first air dam having a full channel height, the assembly further includes a second air dam.
 16. The burner assembly of claim 15 wherein the second air dam is located upstream of the first air dam by between thirty and ninety degrees.
 17. The burner assembly of claim 16 wherein the second air dam has a height that is less than the full channel height.
 18. The burner assembly of claim 14, further comprising: a plate disposed in said center opening and including a slot for holding a pilot light burner head. 